Pump



March 26, 1968 H. K. HETZ 3,374,750

PUMP

Filed July 28, 1966 5 Sheets-Sheet 1 Mam I Y 77 lad:

J, 7i i IN T Z BY HEINZ K. LESTER 4.:

ATTYS.

March 26, 1968 Filed July 28, 1966 FICA.

' H. K. HETZ 3 Sheets-Sheet 2 o 0 Q 0 0 0 o INVENTORI HEINZ K. HETZ BY WATTYS..

H. K. HETZ March 26, 1968 PUMP Filed July 28, 1966 3 Sheets-Sheet ATTYS.

United States Patent 3,374,750 PUMP Heinz K. Hetz, Doylestown, Pa.,assignor to Yarway Corporation, Philadelphia, Pa., a corporation ofPennsylvania Filed July 28, 1966, Ser. No. 568,528 13 Claims. (Cl.103152) The present invention relates to a rotary pump, and hasparticular application to an orbiting piston pump for supplying apulsating pumping fluid to the pumping chamber of a diaphragm pump.

In the operation of a diaphragm pump wherein the pumping liquid isrepeatedly surged into the pumping chamber of the diaphragm pump, thereis a tendency for the entrapped air to accumulate in the pumping chamberand to produce a pocket of air in the pumping chamber which detractsfrom the operating efliciency of the diaphragm pump. Furthermore, inpumps of this character, the adjustment to provide a variation in thethroughput of working fluid in the diaphragm pump either entails ashutdown of the pump and an adjustment of the operating mechanisms orprovides within the pump complicated adjusting linkages which reduce theaccuracy of adjustment and introduce moving parts which are subject tofrictional wear with the resultant reduction in mechanical efliciencyand the need for periodic shut-downs for maintenance.

With the foregoing in mind, the present invention provides a novel pumparrangement having improved means for venting air or other entrappedgaseous fluid to prevent the formation of air or gas pockets within thepumping chamber of the diaphragm pump.

The present invention also provides an improved pump wherein the strokeof the pumping element may be accurately controlled without interruptingoperation of the pump.

Another object of the present invention is to provide a novel pump ofthe diaphragm type wherein the pumping chamber is supplied with apulsating supply of pumping liquid from a rotary pump having areciprocating piston mounted within a radial recess in the rotor, therecess being positioned adjacent the pumping chamber of the diaphragmpump to reduce to a minimum loss occasioned by elongated pumping fluidconduits.

More specifically, the present invention provides an improved adjustmentmechanism of this type wherein the adjustment is linear.

The present invention also provides a pump of the stated type whereinthe rotor is mounted in a closed casing containing pumping fluid whereinany solid particles entrained in the pumping fluid may settle to thebottom to avoid interference With the rotor operation and entrapped airwill rise to the top where it may be vented to the atmosphere.

Still a further object of the present invention is to provide a novelpump of the above type which is relatively compact, having a shortoverall length and a very short distance between bearings supporting therotor. The construction of the pump of the present invention permits theorbiting piston and diaphragm to be mounted in extremely close relationto provide a sturdy, compact unit.

All of the objects of the invention are more fully set forth hereinafterwith reference to the accompanying drawings wherein:

FIG. 1 is a view in side elevation of a pump made in accordance with thepresent invention;

FIG. 2 is a plan view of the pump shown in FIG. 1;

FIG. 3 is a fragmentary view in end elevation of the oump;

FIG. 4 is an enlarged sectional view taken on the line 4-4 of FIG. 2;

FIGS. 5, 6 and 7 are sectional views taken on the lines 5-5, 66 and 77,respectively, of FIG. 4.

Referring now to the drawing, the illustrated pump comprises a casing 10having at one end a work fluid inlet 11 and a work fluid outlet 12. Atthe other end, a gear case housing 14 receives a rotor shaft 15 andcontains gear connections 1-6 to a drive motor 17. An adjusting memberis provided at 18 on the front of the casing 10.

Internally, the casing 10 has a wall member 21 which divides the casinginto a diaphragm housing 22 and a rotor housing or chamber 23. Adiaphragm 25 is positioned between diaphragm plates 26 and 27 in thediaphragm housing to divide the housing into a pumping chamber 28 and awork chamber 29. The inlet 11 is connected to the Work chamber 29through a non-return valve 31 and the outlet 12 is connected to the workchamber 29 through a non-return valve 32. The valves 31 and 32 operateupon flexure of the diaphragm 25 to efiect flow of work fluid upwardlythrough the work chamber 29.

In order to effect flexure of the diaphragm 25, means is provided toflow surges of pumping fluid into and out of the pumping chamber 28. Tothis end, a rotor 41 is mounted in the rotor housing 23, for example, bytapered roller bearings 42 and 43 on an inner rotor shaft 44 and theouter rotor shaft 15, respectively. The rotor 41 has a radial recess 45therein which slidably mounts a piston 46. The piston 46 is biasedoutwardly by a spring 47 which seats in the bottom of the recess asindicated at 43. The bottom of the recess 45 communicates with thepumping chamber 28 through a port 51 and a hollow transfer member 52. Acentral venting aperture is provided between the interior of the member52 and the center of the rotor recess as indicated at 53 to permit theescape of air from the center of the recess 45.

In order to obtain a pumping action as the rotor is rotated by the drivemotor 17, an eccentric guide means 55 surrounds the rotor in engagementwith the exposed end of the piston 46. The guide means is adjustablympunted in the casing 19 to control the throw of the piston 46 and tothis end, the guide means 55 comprises an outer control member 56 havingoutwardly projecting stub shafts 57 and 58, respectively, engaging inbores 59 and 60 in the casing 10.

As shown in FIG. 5, adjusting means is provided to displace the stubshafts 57 and 58 in their bores to control the eccentricity of thecontrol member 56 to the rotor 41. To this end, the stub shaft 58 isprovided with an internally threaded socket 62 adapted to threadablyengage an end portion 63 on an adjusting screw 64. The body 65 of theadjusting screw 64 is threaded into the casing and may be locked inplace by a locking pin 66 cooperating with a locking slug 67 in thescrew body 65. The thread pitch of the end portion 63 is less thanthread pitch of the body portion so that the axial movement of theadjustment screw is larger than the travel of the control member, forexample, 1" axial movement of the adjustment screw will result in a /2in. travel of the control member, thus providing improved resolution atthe inicrometer dial readout. The adjusting knob 18 is fixed to thescrew 64 by a set screw 68 and index markings are provided at 69 (seeFIGS. 2 and 3) to indicate the position of the control member in therotor housing 23. In order to prevent hydraulic lock of the shaft 57 inthe recess 59, a flat is provided on the shaft 57 as indicated at 71 toallow entrapped fluid to escape from the recess 59. This adjustment ofthe control member provides for a linear relation between adjustingmovement of the adjusting knob 18 and adjustment of the throw of the 3 7piston 46 to enable as closely as possible a linear regulation of thethrough-put of the diaphragm pump. There is minimum lost motion in theadjustment, and the adjustment may be performed without arrestingoperation of the pump.

In order to reduce friction and the resultant wear, means is provided toenable rolling engagement of the piston end against the guide. To thisend, a liner or reaction ring 73 is mounted for relative rotation withinthe control member 56 by means of rollers 74. Thus, the liner 73 mayrotate with the rotor 41 to eliminate sliding friction between thepiston 46 and the guide means 55. The control member 56 and liner 73function as a roller bearing to eliminate sliding friction.

In the operation of the pump, the rotor housing 23 is filled withpumping liquid, for example, to the level indiciated at A in FIGS. 4'and5. As the rotoris rotated by the motor 17, the eccentricity of the guidemeans 55 displaces the piston within the radial recess 45. Inwarddisplacement of the piston 46 pumps the pumping fluid from the bottom ofthe recess 45 through the port 51 and discharge outlet in the member 52into the pumping chamber 28 thereby flexing the diaphragm 25 outwardlytoward the outer diaphragm plate 26. Flexing the diaphragm outwardlyforces working liquid in the work chamber 29 out through the valve 32into the outlet 12. As the rotor 41 continues to rotate, the spring 47displaces the piston 46 outwardly thereby drawing pumping liquid fromthe chamber 28 through the member 52 and port 51 into the bottom of therecess 45. Withdrawal of the pumping liquid from the chamber 28 flexesthe diaphragm 25 toward the inner diaphragm plate 27 drawing Workingliquid into the chamber 29 from the inlet 11 through the inlet valve 31.

Air or other gaseous fluid in the pumping liquid which might otherwiseaccumulate behind the piston 46 are free to escape into the dischargeoutlet 52 through the venting aperture 53 and into the pumping chamber28. Bubbles in the pumping chamber 28 rise to the top, and in accordancewith the invention, means is provided to vent the accumulated gaseousfluid from the pumping chamber to thereby prevent deterioration of thepumping action. As shown in FIGS. 4, 5 and 7, vent means is provided toperiodically remove a predetermined volume of fluid from the top of thepumping chamber 28 and to replace a like volume of pumping liquid. T 0this end, a vertical passage 80 is provided in the wall 21 at the top ofthe pumping chamber 28. The passage extends upward ly through the walland is closed at its uppermost end by a plug 83. A connecting passage 84connects the passage 80 with the rotor housing 23 adjacent the upper endof the latter.

For effective operation, the pumping'chamber 28 must be continuouslyclosed and to prevent escape of pumping fluid from the pumping chamber28 during normal operation of the pump, the passage 80 is closed by aventing shaft 85 which divides the passages 80 into an upper branch 81and a lower branch 82. The venting.

shaft 85 has pockets 86 in registry with the vertical passage 82 andmeans is provided to displace the shaft 85 periodically to cause thepockets to rotate'from a position in registry with the upper branch 81of the passage. Thus, during the operation of the pump, the pocket 86which is in registry with the lower branch 82, is filled with fluid. Ifbubbles have accumulated in the pumping chamber 28, the bubbles willtravel into the lower branch 82 and into the pockets 86 displacing anypumping fluid which may be contained therein. When the shaft is rotated,thefluid in the pocket, whether pumping fluid or' gaseous fluid from thebubbles, is carried into the upper branch 81 of the passageway. At thesame time, pumping the level of the pumping fluid in the upper branch 81falls below the level of the connecting passage 84, additional pumpingfluid is free to enter the passage through the passage 84 from the rotorchamber 23. Thus, the upper branch 81 is continuously supplied withpumping fluid to replace the gaseous and/or pumping fluid removed fromthe lower branch 82.

The shaft 85 is rotated step by step by the rotation of the rotor. Toaccomplish this, a crank 91 is mounted on the inner end of the shaft 85through a one-way clutch 92. The free end of the crank 91 has a followerroller 93 thereon which is biased by a spring 94 against a cam ring 95formed integrally with the rotor 41. In the present instance, the camring 95 has a single lobe thereon which operates during each revolutionof the rotor to oscillate the follower 93 and therefore the lever 91 anangular distance of about 15 so as to index the shaft 85 a similaramount. Thus, the shaft 85 is rotated in steps as the rotor rotates. Inthe present instance, the shaft is rotated one full turn for every 24turns ofthe rotor 55 of the rotary pump.

Suitable pressure relief means is provided to prevent overloading of thepump. To this end, a relief passageway 75 is provided in the wall member21, in the present the pumping chamber, for example, during initial fillof the pump with pumping fluid.

In the event of loss of pressure fluid from the pumping 7 chamber 28,make-up fluid is automatically supplied from the rotor chamber 23. Tothis end, a make-up inlet is provided in the bottom of the pumpingchamber which is normally closed by a check valve 96. The check valveincludes a valve element 97 which is normally biased closed by a spring98. When the pressure in the pumping chamber 28 is reduced sufficientlyto allow the pressure in the rotor chamber 23 to overcome. the bias ofthe spring 7 9-8, the valve element 97 opens the valve to admit pumpingfluid from the rotor chamber 23 through the port 99. An operator 101 isprovided to relieve the pressure of the spring 98 in order to permitopening of the valve 97, for example, during initial fill and duringdraining to allow rapid flow of pumping fluid between the rotor chamber23 and pumping chamber 28.

In order to provide for draining'of the pumping fluid, a drain plug isprovided in the rotor chamber 23 at the bottom thereof as indicated at10-3 so that the pumping fluid and any accumulated sludge at the bottomof the rotor chamber may be discharged. During normal operation of thepump, the chamber is vented by releasinga vent stop 104 at the top ofthe chamber to permit expan sion and contraction of the pumping liquid.Air flow during expansion or contraction of the pumping liquid occursthrough a vent hole 102 in the bottom of the gear case 14. Duringshipping of the pnmp, the vent stop 104'is in the closed position toprevent loss of liquid. A quick fill plug is also provided at the top ofthe chamber as indicated at 105. l

The drawings illustrate a rotary pump having a single radial recess andpistonrin the rotor, but is apparent that the rotor may be elongated toaccommodate a plurality of pistons working together or in opposition toone another as desired. Furthermore, the illustrated embodiment of theinvention utilizes an axial discharge conduit from the rotor recess andit may be desired to discharge the fluid radially into a pressurechamber in fluid com-- munication with the pumping chamber withoutadversely affecting the stiffness provided by the juxtaposition of therotor with the pumping chamber.

While a particular embodiment of the invention has been illustrated anddescribed herein, other changes and modifications may be made thereinand thereto within the scope of the following claims.

I claim:

1. In a pump assembly comprising a diaphragm pump having a pumpingchamber, a work chamber, a valvecontrolled inlet and valve-controlledoutlet for said work chamber, and a pumping port for admitting apulsating liquid pumping fluid to said pumping chamber to flex thediaphragm and effect pumping of work fluid through said work chamber;and a rotary pump for supplying a pulsating pumping fluid to saidpumping port; the improvement wherein said pumping chamber includesmeans to vent gaseous fluid from said pumping chamber comprising apassage in the top of the pumping chamber, a shaft intersecting saidpassage to separate the passage into a lower branch and an upper branch,said shaft including pocket means operable upon displacement of saidshaft between first and second positions to alternatively registerrespectively with the top of said lower branch and the bottom of saidupper branch, means to introduce liquid pumping fluid into said upperbranch, and means to displace said shaft successively between said firstposition wherein said pocket receives a predetermined volume of fluidfrom the top of said lower branch, and said second position wherein saidpocket receives said predetermined volume of liquid pumping fluid fromthe bottom of said upper branch, whereby any gaseous fluid in saidpumping chamber is transferred to said upper branch upon displacement ofsaid shaft from said first position to said second position and pumpingfluid is transferred from said upper branch to said chamber upondisplacement of said shaft from said second position to said firstposition.

2. A pump assembly according to claim 1 wherein said means to displacethe shaft comprises a follower carried by said shaft and a cam ringcarried by said rotary pump and engaging said follower, whereby saidshaft is displaced alternately between said first and second positionsupon rotation of said rotary pump.

3. A pump assembly according to claim 1 wherein said upper and lowerbranches are in vertical alignment and said shaft is mounted forrotation intermediate said branches, said displacing means beingoperable to rotate said shaft in steps between said first and secondpositions.

4. A pump assembly according to claim 3 wherein said displacing meansincludes a follower carried by said shaft, a one-way clutchinterconnecting said follower to said shaft, and a cam carried by saidrotary pump to engage and oscillate said follower to thereby rotate saidshaft in steps.

5. A pump assembly according to claim 1 wherein said rotary pumpcomprises a rotor housing adjacent said pumping chamber, a rotor mountedfor rotation in said housing and having a substantially radial recessformed therein, a piston mounted for reciprocating movement within saidrecess, an adjustable guide within said housing surrounding said rotorin engagement with the outer end of said piston to 'controlreciprocating movement of said piston upon relative rotation of saidrotor and said guide means, and a fluid discharge port connected to saidrecess at its inner end and connected to said pumping port to conductsaid pulsating liquid pumping fluid to said pumping chamber uponreciprocation of said piston, said rotor housing adapted to be filledwith pumping fluid, said means to introduce pumping fluid into saidupper branch comprising a connecting passage intermediate said upperbranch and said rotor housing.

6. A pump assembly according to claim 5 wherein said guide meanscomprises a control member mounted in said housing eccentric to saidrotor, and a reaction ring mounted for free rotation interiorly of saidcontrol member and engaging the outer end of said rotor piston.

7. A pump assembly according to claim 6 including means to adjust theeccentricity of said control member from the outside of the housingincluding an adjusting screw threaded in said housing and engaging saidcontrol member whereby the eccentricity of said guide means may beadjusted during rotation of said rotary pump to thereby control -thepulsations of said pumping fluid and thus the through-put of thediaphragm pump.

8. A pump assembly according to claim 7 wherein said adjusting screw isalso threaded into said control member with a different pitch from thethreading in the housing to thereby provide a fine adjustment which isfree from substantial play.

9. In a pump assembly comprising a housing, a rotor mounted within saidhousing, a radial recess formed in said rotor, a piston mounted forreciprocating movement within said radial recess, an adjustable guidewithin said housing engaging said piston, and surrounding said rotor tocontrol reciprocating movement of said piston upon relative rotationbetween said rotor and said guide, drive means to cause relativerotation between said rotor and said guide, adjusting means accessiblefrom the exterior of said housing to adjust the position of said guiderelative to said rotor, a pumping chamber remote from said rotor, afluid discharge outlet in said rotor in fluid communication with saidradial recess, said discharge outlet terminating in fluid communicationwith said pumping chamber, said housing being completely filled with apumping fluid, and vent means to remove a predetermined volume ofpumping and/ or gaseous fluid from the uppermost portion of said pumpingchamber at predetermined intervals during the pumping operation anddischarge the same into the pumping fluid in said housing, said ventmeans operable to replace said predetermined volume of pumping and/ orgaseous fluid removed from said pumping chamber with an equal volume ofpumping fluid.

10. Apparatus in accordance with claim 9 wherein said guide meansincludes a control member interconnected with said adjusting means, anda reaction ring mounted for free rotation Within said control member andengaging said piston, said control member being adjustable in adirection normal to the axis of said rotor from a first limit positionconcentric with the axis of said rotor to a second limit position offsetfrom the axis of said rotor.

11. Apparatus in accordance with claim 9 wherein a wall me'mberseparates the upper end of said pumping chamber from the fluid Withinsaid housing and said vent means includes a rotatable shaft extendingthrough said wall member, at least two pockets formed in the peripheralsurface of said rotatable shaft, a lower branch passage in said wallmember extending from said rotatable shaft to the uppermost portion ofsaid pumping chamber, an upper branch passage in said wall memberextending from said rotatable shaft and connected to the pumping fluidin said housing, and drive means for said shaft operable upon relativerotation between said rotor and said guide to cause rotation of saidshaft to move a pocket in said shaft from a position in fluidcommunication with said lower branch to a position in fluidcommunication 'with said upper branch and simultaneously therewith movethe second pocket from a position in fluid communication with said upperbranch to a position in fluid communication with said lower branch.

12. In a pump assembly comprising a housing, a rotor mounted within saidhousing, a radial recess formed in said rotor, a piston mounted forreciprocating movement Within said radial recess, an adjustable guidewithin said housing engaging said piston, and surrounding said rotor tocontrol reciprocating movement of said piston upon relative rotationbetween said rotor and said guide, drive means to cause relativerotationbetween said rotor and said guide, a pumping chamber remote from saidrotor, a fluid discharge outlet in said rotor in fluid communicationwith said radial recess, said discharge outlet ter- 7 minating in fluidcommunication with said pumping chamber, said housing being completelyfilled with a pumping fluid, a control member, means adjustably mountingsaid control member in said housing for movement in a direction normalto the aXis of said rotor, and means interconnecting said control memberwith said adjustable guide to move said adjustable guide from a firstlimit position concentric with the axis of said rotor to a second limitposition offset from the axis of said rotor upon adjusting movement ofsaid control member.

13. In the pumping chamber of a pump assembly, means to vent gaseousfluid from said pumping chamber comprising a passage in the top of thepumping chamber, a shaft intersecting said passage to separate thepassage into a lower branch and an upper branch, said shaft includingpocket means operable upon displacement of said shaft between first andsecond positions to alternatively register respectively with the top ofsaid lower branch and the bottom of said upper branch, means tointroduce liquid pumping fluid into said upper branch, and means todisplace said shaft successively between said first position whereinsaid pocket receives a predetermined volume of-fluid from the top ofsaid lower branch, and said second position wherein said pocket receivessa-id predetermined Wolume of liquid pumping fluid fromthe bottom ofsaid upper branch, whereby any gaseous fluid in said pumping chamber istransferred to said upper branch upon displacement of said shaft fromsaid first position to said second position and pumping fluid istransferred from said upper branch tosaid chamber upon displacement ofsaid shaft from said second position to said first position. i 7

2/1954 Tucker 10338 3/1961 Bennett 103-44 20 ROBERT M. WALKER, PrimaryExaminer.

1. IN A PUMP ASSEMBLY COMPRISING A DIAPHRAGM PUMP HAVING A PUMPINGCHAMBER, A WORK CHAMBER, A VALVECONTROLLED INLET AND VALVE-CONTROLLEDOUTLET FOR SAID WORK CHAMBER, AND A PUMPING PORT FOR ADMITTING APULSATING LIQUID PUMPING FLUID TO SAID PUMPING CHAMBER TO FLEX THEDIAPHRAGM AND EFFECT PUMPING OF WORK FLUID THROUGH SAID WORK CHAMBER;AND A ROTARY PUMP FOR SUPPLYING A PULSATING PUMPING FLUID TO SAIDPUMPING PORT; THE IMPROVEMENT WHEREIN SAID PUMPING CHAMBER INCLUDESMEANS TO VENT GASEOUS FLUID FROM SAID PUMPING CHAMBER COMPRISING APASSAGE IN THE TOP OF THE PUMPING CHAMBER, A SHAFT INTERSECTING SAIDPASSAGE TO SEPARATE THE PASSAGE INTO A LOWER BRANCH AND AN UPPER BRANCH,SAID SHAFT INCLUDING POCKET MEANS OPERABLE UPON DISPLACEMENT OF SAIDSHAFT BETWEEN FIRST AND SECOND POSITIONS TO ALTERNATIVELY REGISTERRESPECTIVELY WITH THE TOP OF SAID LOWER BRANCH AND THE BOTTOM OF SAIDUPPER BRANCH, AND MEANS TO INTRODUCE LIQUID PUMPING FLUID INTO SAIDUPPER BRANCH, AND MEANS TO DISPLACE SAID SHAFT SUCCESSIVELY BETWEEN SAIDFIRST POSITION WHEREIN SAID POCKET RECEIVES A PREDETERMINED VOLUME OFFLUID FROM THE TOP OF SAID LOWER BRANCH, AND SAID SECOND POSITIONWHEREIN SAID POCKET RECEIVES A PREDETERMINED VOLUME OF LIQUID PUMPINGFLUID FROM THE BOTTOM OF SAID UPPER BRANCH, WHEREBY ANY GASEOUS FLUID INSAID PUMPING CHAMBER IS TRANSFERRED TO SAID UPPER BRANCH UPONDISPLACEMENT OF SAID SHAFT FROM SAID FIRST POSITION TO SAID SECONDPOSITION AND PUMPING FLUID IS TRANSFERRED FROM SAID UPPER BRANCH TO SAIDCHAMBER UPON DISPLACEMENT OF SAID SHAFT FROM SAID SECOND POSITION TOSAID FIRST POSITION.